The Confederation and the Cantons shall endeavour to achieve a balanced and sustainable relationship between nature and its capacity to renew itself and the demands placed on it by the population.
#Overview
Art. 73 Cst. enshrines the principle of sustainable development in the Federal Constitution. The provision obligates the Confederation and the cantons to strive for a balanced relationship between the use of nature and the preservation of nature. The utilization of nature may not exceed its regenerative capacity (Griffel, BSK BV, Art. 73 N. 5).
Affected are all state authorities in decisions with environmental impacts. Private parties cannot directly invoke Art. 73 Cst., as the norm has a programmatic character and does not establish immediate rights (Biaggini, BV Kommentar, Art. 73 N. 3). The practical implementation occurs through special laws such as the Environmental Protection Act (Art. 1 EPA) or the Spatial Planning Act (Art. 1 SPA).
The principle of sustainability acts as an interpretative principle for all state decisions. In conflicts of interest between economy and environment, authorities must find a sustainable balance. The Federal Supreme Court applied this in the Grenchenberg wind farm case: wind energy was authorized, but with conditions to protect endangered bird species (BGE 148 II 36). This promotes renewable energy without destroying nature.
In case law, Art. 73 Cst. is concretized in various areas: The Federal Supreme Court qualified a municipal initiative for renewable heating as implementation of the principle of sustainability (BGE 149 I 291). In cases of aircraft noise or gravel extraction, long-term environmental consequences must be taken into consideration.
However, the principle is not justiciable in the sense of enforceable individual rights. It remains controversial whether ecological limits apply absolutely or can be weighed against economic advantages (strong versus weak sustainability according to Griffel, BSK BV, Art. 73 N. 5 versus economy-oriented interpretations).
#Doctrine
#1. History
N. 1 Art. 73 Cst. was newly introduced as part of the total revision of the Federal Constitution in 1999. The provision explicitly enshrined the principle of sustainable development at the constitutional level for the first time. In the Federal Council's Dispatch of 20 November 1996 on a new Federal Constitution (BBl 1997 I 1, 235 f.), the sustainability principle is described as a «guiding principle for all state action» which should harmonise the three dimensions of ecology, economy and society.
N. 2 The constitutional assembly adopted the provision without significant changes from the Federal Council's constitutional draft. The parliamentary debates showed broad consensus on the need to enshrine the concept of sustainable development, internationally established since the Rio Conference of 1992, in the Swiss constitution as well. At the same time, there was awareness of the programmatic nature of the provision (Griffel, BSK BV, Art. 73 N. 1).
#2. Systematic classification
N. 3 Art. 73 Cst. stands at the beginning of Section 4 «Environment and Spatial Planning» and serves as a hinge between the general guiding principles (→ Art. 2 Cst.) and the more concrete environmental protection provisions (→ Art. 74 ff. Cst.). As a cross-cutting principle, the norm shapes all policy areas and must be considered when interpreting other constitutional provisions, particularly → Art. 54 Cst. (Foreign Affairs), → Art. 75 Cst. (Spatial Planning), → Art. 77 Cst. (Forests), → Art. 104 Cst. (Agriculture) and → Art. 126 Cst. (Financial management) (Griffel, BSK BV, Art. 73 N. 4).
N. 4 The sustainability principle is closely linked to the state objective of sustainable development enshrined in Art. 2 Cst. While Art. 2 Cst. defines sustainable development as a general state objective, Art. 73 Cst. concretises this goal for the relationship between humans and nature. The systematic position underlines that sustainability must not be reduced to environmental protection, but should be understood as an integrative concept (Flückiger, Le développement durable en droit constitutionnel suisse, URP 2006, 1 ff., 8).
#3. Elements of the provision / Content of the norm
N. 5 Addressees of the norm: Art. 73 Cst. is addressed to both the Confederation and the cantons. The wording «shall endeavour» makes clear that both state levels are obligated to realise the sustainability principle. This shared responsibility corresponds to the federalist structure of environmental policy (Petitpierre-Sauvain, Fondements écologiques de l'ordre constitutionnel suisse, 2003, 89).
N. 6 «A balanced relationship in the long term»: The term «in the long term» refers to the intergenerational dimension of sustainability. The present generation may not exploit natural resources to such an extent that future generations are restricted in satisfying their needs. The «balanced relationship» requires a balance between use and regeneration of natural resources. This excludes overuse but allows moderate exploitation within the limits of regenerative capacity (Griffel/Rausch/Marti, Umweltrecht – Ein Lehrbuch, 2020, § 2 N. 45).
N. 7 «Regenerative capacity of nature»: This term refers to the capacity of ecosystems to regenerate and maintain their functions. Central is respect for natural cycles and regeneration times. For renewable resources, the rate of use must not exceed the rate of regeneration; for non-renewable resources, economical use is required (Mahaim, Le principe de durabilité et l'aménagement du territoire, 2014, 125 f.).
#4. Legal consequences
N. 8 Art. 73 Cst. primarily takes effect as an interpretive principle and optimisation requirement. All state organs are obligated to consider the sustainability principle in their decisions and to realise it within the scope of their competences. This applies to legislation as well as to law enforcement and jurisprudence (Griffel, BSK BV, Art. 73 N. 11).
N. 9 The case law of the Federal Supreme Court demonstrates the practical relevance of the sustainability principle: In BGE 148 II 36 E. 13.6, the Federal Supreme Court held that wind power use only meets the requirements of the sustainability principle if a balanced relationship in the long term between renewable energy production and nature conservation is ensured. In BGE 149 I 291, a municipal initiative for renewable heating systems was qualified as a concretisation of Art. 73 Cst.
N. 10 As a programmatic norm, Art. 73 Cst. does not establish immediate subjective rights. Private parties cannot directly invoke the provision to demand concrete measures or require omissions. The norm requires concretisation through legislation, particularly through the Environmental Protection Act, the Spatial Planning Act and energy legislation (Biaggini, BV Kommentar, 2. Aufl. 2017, Art. 73 N. 3).
#5. Controversies
N. 11 Strong versus weak sustainability: In doctrine, there is a fundamental controversy about the relationship between the three sustainability dimensions. The strong conception of sustainability, represented by Griffel (BSK BV, Art. 73 N. 5) and Rausch/Marti (in: Griffel/Rausch/Marti, Umweltrecht, § 2 N. 47), postulates that compensation between areas – particularly at the expense of the environment – is not permissible. Ecological capital must be respected as an absolute limit. By contrast, the weak conception allows a certain substitution between natural, physical and human capital, as long as total capital is preserved. This position is found implicitly in economy-oriented interpretations of the sustainability principle.
N. 12 Justiciability of the sustainability principle: Another point of contention concerns legal enforceability. Flückiger (URP 2006, 15) and Mahaim (Le principe de durabilité, 2014, 287) as well as Brahier (Installations dangereuses et aménagement du territoire, 2018, 195) take the view that the sustainability principle is justiciable and can establish enforceable obligations in individual cases. The prevailing doctrine, represented by Griffel, Rausch, Marti (Umweltrecht, § 2 N. 51), Aubert (Petit commentaire BV, Art. 73 N. 8), Mahon (Petit commentaire BV, Art. 2 N. 12) and Biaggini (BV Kommentar, Art. 73 N. 3), argues instead that the sustainability principle is not justiciable, as it is not normatively sufficiently condensed to establish rights and obligations enforceable by administrative order in individual cases.
N. 13 International law dimension: It is also disputed whether the concept of sustainable development has already crystallised into customary international law. While some voices in the literature affirm this, Keller/von Arb (Nachhaltige Entwicklung im Völkerrecht, URP 2006, 210, 226) describe this view as «audacious». The international law quality is significant for the interpretation of Art. 73 Cst. in light of Switzerland's international obligations (Epiney/Scheyli, Umweltvölkerrecht, 2. Aufl. 2021, 95 ff.).
#6. Practical guidance
N. 14 Concretisation in legislation: The sustainability principle is concretised through numerous federal acts, particularly the Environmental Protection Act (precautionary principle), the Spatial Planning Act (economical land use), the Energy Act (promotion of renewable energies) and the CO₂ Act (climate protection). When drafting and revising enactments, Art. 73 Cst. is to be used as an interpretive aid.
N. 15 Balancing of interests: In practice, the sustainability principle frequently manifests itself in complex balancing of interests. As the Federal Supreme Court demonstrated in BGE 148 II 36, the various sustainability dimensions must be carefully weighed against each other in major projects. Solutions should be sought that do justice to all dimensions as far as possible – in the concrete case through operational restrictions to protect endangered species while simultaneously enabling wind energy use.
N. 16 Burden of proof and investigative duties: Authorities have a comprehensive duty to investigate the sustainability impacts of their decisions. This includes particularly the long-term consequences for the environment, but also social and economic aspects. The sustainability assessment must be transparently presented in the decision-making basis.
N. 17 Monitoring and adaptive administration: The sustainability principle requires continuous review and adaptation of state measures. Permits for environmentally relevant projects should therefore contain monitoring obligations and adaptation reservations in order to respond to new findings. This adaptive administrative practice corresponds to the dynamic nature of the sustainability principle.
#Case Law
#Energy Transition and Renewable Energy
BGE 149 I 291 of 3 May 2023 Initiative for conversion to renewable heating systems as constitutionally compliant The initiative "Hochdorf heizt erneuerbar - ab 2030 erst recht" does not violate higher-ranking law and may be submitted to the voters. The objective of the initiative can be understood as a step towards ecologically sustainable development (Art. 73 Federal Constitution) and is based on the compelling public interest in sustainable development.
"The regulation proposed by the disputed initiative can be understood as a step towards more ecologically sustainable development and thus as a concretisation of Art. 73 Federal Constitution. It can therefore rely on the compelling public interest in sustainable development."
BGE 148 II 36 of 24 November 2021 (Grenchenberg Wind Farm) Balancing interests between renewable energy and nature conservation The Federal Supreme Court confirmed the Grenchenberg wind farm despite conflicts with nature conservation. In the overall balancing of interests, the national interest in the use of wind energy must be considered, particularly against the background of climate change and Switzerland's climate goals. The aim is to achieve a balance of interests that reduces the risk to biotope and species protection to an acceptable level without making the use of renewable wind energy impossible.
"National interest in the use of wind energy at Grenchenberg, particularly against the background of climate change and Switzerland's climate goals. [...] The aim is to achieve a balance of interests, i.e. the risk of collisions and habitat disruption is to be reduced to a level acceptable for biotope and species protection without making the use of renewable wind energy impossible."
#Climate Protection and Public Transport
BGE 149 I 182 of 31 March 2023 Principle of sustainability and free public transport The Fribourg constitutional initiative for free public transport violates Art. 81a para. 2 Federal Constitution. The principle of sustainability (Art. 73 Federal Constitution) and the Paris Climate Agreement do not justify the complete free provision of public transport. The requirement that certain users contribute to the costs does not violate either the principle of sustainability or the climate goals.
"That certain users of public transport are required to contribute to its costs does not violate either the principle of sustainability (Art. 73 Federal Constitution) or Art. 2 No. 1 of the Paris Climate Agreement."
#Long-term Planning and Resource Protection
Judgment 1A.115/2003 of 23 February 2004 (Wangental Extraction Focus Area) Sustainable management of mineral resources in long-term planning The development regulation for a 50-year gravel extraction is fundamentally permissible. Long-term planning corresponds to the requirement for sustainable use of natural resources. Art. 73 Federal Constitution requires a balanced relationship between the use of natural resources and their regenerative capacity, which must be considered in the dimensioning of extraction areas.
Relevant for the sustainable management of natural resources and long-term spatial planning within the meaning of Art. 73 Federal Constitution.
#Environmental Protection and Immissions
BGE 136 II 263 of 8 June 2010 Aircraft noise and sustainable transport system When assessing compensation claims for excessive noise pollution from air traffic, the principles of sustainability must be observed. The balancing of interests between mobility needs and environmental protection must take account of the principle of sustainability.
Relevant for the balanced relationship between transport needs and environmental protection within the meaning of Art. 73 Federal Constitution.
BGE 138 II 331 of 6 June 2012 Noise protection and sustainable development When authorising noise-intensive installations, a sustainable balancing of interests between economic needs and environmental protection is required. The noise protection provisions concretise the requirement for sustainable development.
Relevant for the balance between economic use and environmental protection within the framework of sustainable development.
#Animal Protection and Ethical Sustainability
BGE 135 II 384 of 7 October 2009 (Primate Animal Experiments) Animal experiments and sustainable research ethics Animal experiments with non-human primates require particularly careful balancing of interests. The principle of sustainability also encompasses ethical aspects in dealing with animals and nature. The balancing of interests must consider the long-term relationship between humans and nature.
Relevant for the ethical dimension of sustainability and respectful treatment of nature within the meaning of Art. 73 Federal Constitution.